The chief constable has revealed that just one in seven burglaries, robberies and car crimes in the Thames Valley were solved last year.
Chief Constable Sara Thornton said the crime detection rate was 14%, despite a county-wide fall in crime.
"The best forces are over the 20% mark and I think we should be aiming for that," she said.
"The numbers of crimes we were solving had got too low, we're working to build them up again."
The chief constable said crime was falling overall and that crime prevention was a priority for the force.
Thames Valley Police received a "poor" rating for solving crimes in its annual assessment from inspectors this year.
The Police Report Card by HM Inspectorate of Constabulary gave the force an overall rating of "fair".
Jess Todd, from Newbury in Berkshire, said she was not surprised that crime detection rates were low for vehicle crime.
"I've had my wing mirror kicked off, I've had bottles put through the windscreen and scratches put down the side of the car. My friend's car has also been keyed as well," she said.
"I live right in the town centre, one of the nicest bits of Newbury.
"I have reported the crimes, but then I stopped, because they weren't doing anything about it."
BBC South Home Affairs Correspondent Damon Embling said the coalition government was keen to tackle car crime and burglary, but Thames Valley Police were also facing budget cuts of up to 25%.
"Clearly there is still much more room for improvement," he said.
"The Home Secretary Theresa May has launched what she has described as the most radical reform of policing for 50 years.
"She wants less bureaucracy, more police out on the street, and more opportunities for the public to hold their local police forces to account."