Officers had discovered the three victims, aged 25, 28 and 61, with serious injuries at the house in Bushey, a leafy town 20 miles northwest of London, on Tuesday evening. They had died at the scene a short time later.
A huge search involving armed officers was launched for suspect, Kyle Clifford, with police warning the public not to approach the 26-year-old.
"Following extensive enquiries, the suspect has been located and nobody else is being sought in connection with the investigation at this time," Detective Inspector Justine Jenkins from the local Major Crime Unit said in a statement.
Police said Clifford had been located in north London and was receiving medical treatment after being found with injuries. No shots were fired by police, the statement added.
The victims are yet to be formally identified but police said they believed Clifford was known to the three women.
Earlier on Wednesday Chief Superintendent Jon Simpson called the incident "horrific", telling reporters a crossbow and possibly other weapons were believed to have been involved.
Friends and colleagues of Hunt expressed their shock at the news.
"Impossible to comprehend the pain. Just know we are all here for you John. We love you pal - racing loves you," ITV horse racing commentator Matt Chapman said on X.
