Blood Pattern Analysis Tells the Stories of Bloody Crimes

October 21, 2025

by Laura L. Sullivan, Public Relations Specialist

Blood can tell a story, and Forensic Science Supervisor Lisa Murphy is skilled at reading that tale.

“We all see blood on a daily basis, but blood analysis is a specialty,” Murphy said. “I had an interest since I first started.” She was lucky enough to have two mentors early in her career, and shadowed them until she could take classes in the specialty. Now because of her skills she was selected as last year's Forensic Science Specialist of the Year for her work on blood pattern analysis on two major cases.

She uses her expertise to help figure out exactly what happened on a crime scene, looking at spatter patterns, blood transfer, and even voids where blood should be but isn’t. Blood evidence can make predictable patterns depending on the weapon used and other factors. A drop may be passive – a drip from a nosebleed, or blood flowing down a hill. Transfer stains are made by things coming into contact with blood, such as a bloody handprint or the smudge of a body being moved. Impact bloodstains come when something such as a bullet or a bludgeon strikes someone. Whenever blood hits a surface the shape of the resulting blood pattern is determined by the velocity, angle of impact, how far the blood traveled, and what kind of surface it lands on.

Some scenes have a few drops, or remnants where a perpetrator tried to clean up. Others have a startling amount of blood. One scene she recalls was particularly gruesome. “The blood on the wall was like fireworks.” Without her extensive training she might have been daunted, but she has a system for analyzing it all.

An expert like Murphy will examine the blood on a scene to try to identify where it came from, what weapon was used, where the suspect and victim were positioned, and what direction the injury came from. She might also be able to tell things like how the victim or suspect moved after the incident, or how many suspects were present.

What information she can find depends on the individual scene. “Sometimes it can give you an indication of what type of weapon you might be looking for based on the blood that you’re seeing. It can also refute or confirm suspect statements.” She recalls a case of a person who claimed they were shot in a drive-by, but the blood told a different story. She could show that the person had shot themselves – which was problematic because that person was a felon who wasn’t allowed to be in possession of a gun, plus the gun was stolen. When they claimed they threw the gun into the backyard the blood showed that they were lying – they bled all over the house but there was no blood at all by the back door.

Blood pattern analysis is both a science and an art. The blood tells a story, but she has to take a lot of photographs and measurements from all angles to document and prove that story. Every drop of blood may be relevant, and any one of them could be the evidence that solves a case.

The precise measurements she takes can help her tell where in space that blood originated – what’s known as the area of convergence or area of origin. Is it at floor level or at standing level? Was someone shot while they were upright or on the floor? If you say you shot someone who was charging you, but the blood shows they were on the ground, a claim of self-defense might crumble.

Sometimes a scene appears to be one thing, but Murphy can prove it is something entirely different by using blood evidence. A scene might seem at first glance to be a suicide, until her analysis of the pattern of blood evidence shows that the person was actually shot from across the room, victim of a homicide. “Maybe you have blood present in certain areas where you shouldn’t have blood, or it’s going in a direction it shouldn’t be. Say I have blood all in one area of the residence, and then lo and behold near the exit I have three drops. Whose blood is this going to be? The oddities of the blood are also important because that could be the suspect’s blood if he’s injured himself in some way.”

Places where blood is not can also be telling. An interruption in the pattern may mean that an object was there at the time the blood pattern was originally caused, but then moved. It could be the body itself, or a crucial piece of evidence like a phone or wallet. She can even get information from blood that can’t be seen with the naked eye. When the evidence is miniscule or on certain surfaces like a dark carpet it can be hard to see. Someone might have even tried to clean up the blood. In both cases, the traces or latent blood can be revealed with luminol, a chemical that reacts with the iron in blood’s hemoglobin and produces a short-lived glow that can be photographed. The revealed blood pattern can be analyzed, or it can be used to collect a DNA sample.

Luckily Pinellas County doesn’t have a lot of cases where her blood pattern analysis can be used, but her education is ongoing. Just recently she attended a class about blood on textiles and fabrics. Whenever there is a major case that needs her expertise, she’ll be there. “The blood tells a story, and you just have to let it tell you that story, and listen to it.”

You can find out more about Lisa Murphy, blood pattern recognition, and a whole lot more on Episode #26 of 56: A Pinellas County Sheriff’s Office Podcast.

New Chaplain Program Supports PCSO Members and Families

by Laura L. Sullivan, Public Relations Specialist

Everyone who works at the Pinellas County Sheriff’s Office – whether they are a deputy on the road, in the jail, or in the courthouse, or one of the many civilian members who support the mission – faces challenges unique to the world of law enforcement. To the gamut of mental health and support services that include the Critical Incident Stress Management Team and the Employee Assistance Program, PCSO has now added the Chaplain Program to offer another alternative.

“Our previous agency chaplain retired,” said Chief Deputy David Danzig, “and the sheriff asked that we look at the program and determine where we wanted to go in the future with the initial thought of creating a larger, more robust program to support our members and their families. In looking at other local agencies and across the country we quickly realized that we were behind our peers, so we formed a committee and began to recruit chaplains from the community who were willing to volunteer their time in support of our members.”

The six new chaplains come from churches throughout the county. Jim Grevenites, a deacon in the Diocese of St. Petersburg who is assigned to St. Raphael Church, started his career as a law enforcement officer in the Chicago suburbs. “I have a passion for law enforcement, I’ve always believed in it and understood what it did. Fred Kunder of St. Jerome’s has been a fire department chaplain, and Kennon Wiley of Calvary Clearwater has been both a law enforcement and fire department chaplain.

“The heartbeat of chaplaincy is to lean in and foster relationships with the men and women who give so much to our citizens and community,” Wiley said. The Chaplaincy program is about giving members and their families one more advocate to help them with any of their struggles. “When life happens, when difficulties come, when questions come to their minds they have an advocate who is there to walk that journey with them,” said Justin Facenda of Calvary Clearwater.

More than anything, the chaplains are there to listen. “The amount of trauma they’re exposed to, it can be hard to process and navigate,” said Justin Cobourne of Central Christian Church. “I’m not here to judge people. I’m here to love people well.”

The Pinellas County Sheriff’s Office is a large, diverse agency with people of many backgrounds and faiths, or of no particular religion at all. The chaplains don’t see any conflict. “No matter what your belief is, we all face the same challenges, so there is a lot more we have in common than is different,” Kunder said. “If we work together and focus on what we have in common then we’re in a better position to help each other.” Grevenites echoes the sentiment. “We’re not here to recruit, we’re not here to bring them into a religion, we’re not here to judge – we’re a confidential set of ears.”

The chaplains have been touring the agency, meeting people and finding out more about the world of law enforcement that they’ll be operating in. “We learned about some of what they do,” said Rich Franz of Central Christian Church, “and the courage that it takes to stand up when people aren’t sure they know what you’re doing or that they want to support you, but you push forward every day.”

They’ve even planned a few family and team-building activities to bring members closer together, and help families understand what their loved ones do at the sheriff’s office. “It’s not just the deputy who is involved in this calling – it’s the whole family,” said Wiley. “It’s not just a journey of one, it is the whole household.” The chaplaincy will serve retired members too.

“Having a robust Chaplain Program is all about relationships,” Chief Deputy Danzig said. “It is our goal that they visit our different areas often and offer encouragement and resources for our members and their families.” “We’re very excited that the sheriff and his team of senior leaders have decided to lean in to providing chaplaincy care,” said Wiley. “We understand that chaplaincy is just one tool of many in the toolbox to provide the care and encouragement that agency members need.”